Numerous applications exist in which batteries, fuel cells, electrical interconnects, ultracapacitors and others benefit from tightly spaced interdigitated stripes of dissimilar materials. These materials can be co-extruded using a co-extrusion print head as disclosed in U.S. Patent Publication 2012/0156364, with a similar but alternative print head being shown in U.S. Pat. No. 7,799,371. Being co-extruded in this context mean that the materials are not mixing as they flow. However, the resulting structures have rectangular geometries in cross sectional form with a straight uniform print in the direction perpendicular to the interdigitated geometries.
However, modeling has shown that non-rectangular cross-section geometries have performance enhancement gains in capacity and energy density. Typically, electrodes result from slot coating processes or thin film and semiconductor fabrication techniques. These methods have not yet reached cost effectiveness for large scale production of structured electrodes.